#include<iostream>
using namespace std;

class Data
{
	friend ostream& operator<<(ostream& d1, Data& d2);
		
public:
	Data(int year, int month, int day) ;
	void print();
	bool operator==(Data cut);
	bool operator!=(Data cut);
	bool operator<=(Data cut);
	bool operator>=(Data cut);
	bool operator>(Data cut);
	bool operator<(Data cut);


	Data& operator+(int cut);
	Data& operator++();
	Data& operator++(int);

	Data& operator-(int cut);
	Data& operator--();
	Data& operator--(int);


	int operator-(Data cut);
private:
	int _year = 1;
	int _month = 1;
	int _day = 1;
};

ostream& operator<<(ostream& d1, Data& d2);